Free Space Optics (FSO): Design and Analysis of a 50km Free Space Optical Communication Link (FSO) operating at 2.5Gbps

Free space optical communication links are important in many applications. The design and analysis of such link depends on appropriate modeling parameters. Opt.Sim is a useful software to implement the design parameters and examine the characteristics of the link. This work is about designing and analyzing a free space optical communication link of 50 km distance, particularly in the atmosphere of Kuala Lumpur. Transmitter part consists of a PRBS generator, a NRZ driver, a Fabry-Perot laser diode, a Mach-Zehnder modulator, a semiconductor optical amplifier, a collimating lens, and a beam expander. FSO link has a 50 km range. The environmental additional attenuation is -4.2 dB and standard deviation of 1.9 dB. The peak noise density of this link is -181.0 dBm/Hz. Receiver part consists of a concave mirror, a receiving telescope, a semiconductor optical amplifier, an optical filter, an APD photo-detector, an electrical amplifier, and an electrical filter. The availability of the system is analyzed by measuring the output power, spectrum power, bit-error-rate, and eye diagram at the receiver of FSO.